Multistrategy Synergy Enhances the Hydrogen Evolution Reaction Catalytic Activity of Transition Metal Phosphides in Wide pH

The hydrogen evolution reaction (HER) is critical for sustainable hydrogen production via water electrolysis, but its practical application is hindered by high energy barriers and the cost of noble metal catalysts. This study presents a highly efficient NiCoP nanocrystal catalyst supported on nitrogen and sulfur codoped reduced graphene oxide (NSrGO). The NiCoP/NSrGO catalyst combines optimized electronic structure via cationic alloying with the enhanced dispersion of active sites and superior conductivity provided by the NSrGO substrate. The resulting catalyst demonstrates excellent HER performance, achieving current densities of 10 mA cm −2 with overpotentials of 115, 236, and 283 mV in acidic, alkaline, and alkalized seawater electrolytes, respectively. The results of density functional theory calculations show that alloying can effectively balance hydrogen adsorption desorption and improve water dissociation kinetics. Additionally, the catalyst maintains long‐term stability in seawater electrolysis, making it a promising candidate for scalable hydrogen production.